Determination of the moduli of deformation of a dam and its rock foundation from data of on-site observations of displacements of the structure

Abstract

1. The moduli of deformation of a concrete dam and its rock foundation can be determined sufficiently reliably and simply from the data of on-site measurements of the vertical and horizontal displacements of the dam and can be used when designing structures situated under analogous conditions and also for checking modern methods of assigning calculated values of the deformation characteristics. 2. The method given here made it possible to determine the volume void ratio of the rock α2rk on which substantially depends the stress state in the “structure-rock foundation” contact zone. The results of determining α2rk were used for preparing standards, particularly Construction Norms and Regulations (SNiP) 2-54-77 “Concrete and Reinforced-Concrete Dams.” 3. Both the effect of water on the reservoir bed (weight of the water) and the seepage forces in the rock should be taken into account when calculating the stress-strain state of a structure together with the foundation. The relationship of these factors depends on the stress-strain state of the rock mass and is determined by α2rk.